The areas of application for soft robotics are still in their infancy, but the potential is promisingly large. As part of an in-house test, the vipro-HEAD 3D print head from ViscoTec was able to print a very small, sophisticated pneumatic actuator – a so-called ‘Soft Gripper’.

Robots are such an integral part of industry these days it is hard to imagine production facilities without them. However, their use requires strict safety measures, especially when they come into contact with people. A new generation of robots drastically minimises the risk of injury and offers other advantages: these new robots are made of a flexible material, such as silicone. The movement of the robot is created by a specific filling and emptying of cavities (often using compressed air or vacuum).

An example of a soft robot already used in industry is the so-called pneumatic gripper. These actuators are characterised in particular by their high flexibility in gripping shapes and the non-destructive handling of fragile objects. However, the production of these flexible grippers is a challenge. The complex geometries and the many cavities make injection molding very complex or, in some cases, impossible. This can be remedied by using additive manufacturing and its immense design flexibility.

Thanks to the high degree of automation in 3D printing, a change in geometry can be achieved with little effort. This makes the process perfectly suited for researching and testing new gripper concepts. Recently a project of this kind was undertaken at the ViscoTec 3D technical centre.

An essential factor in successful printing is the extremely precise processing of the desired material, which is mainly silicone in the case of the Soft Gripper. The vipro-HEAD 3/3 or 5/5 is capable of creating particularly fine structures from silicone – with a layer thickness of 0.2mm. By actively retracting the material, no material drips into unwanted areas and a completely airtight component is achieved.

After initial tests it was found that, with the help of the vipro-HEAD 3/3 or 5/5, pneumatic actuators with very small dimensions can be produced: high-precision, additive-manufactured functional components made of silicone.

Particularly in the field of medical technology, the application possibilities of the miniature grippers are intensively tested. For example, in the area of minimally invasive medical procedures, the lower risk of injury from soft robots is a significant advantage over tools made of metal. For this reason, medical-grade silicone was also used for the tests at ViscoTec, to meet such requirements.